Multi-piece container-steel foil body wall



Sept. 24, 1968 c. E. PALMER MULTI-PIECE CONTAINER-STEEL FOIL BODY WALL Filed on. 24, 1966 2 Sheets-Sheet 1 INVENTOR. CHARLES E. PALMER M 5% his AGENT Sept. 24, 1968 c. E; PALMER MULTI-FIECE CONTAINER-STEEL FOIL BODY WALL Filed 001. 24. 1966 2 Sheets-Sheet B INVENTOR. CHARLES E. PALMER his AGENT United States Patent MULTI-PIECE CONTAINER-STEEL FOIL BODY WALL Charles E. Palmer, Somers, Conn., assignor to Jones &

Laughlin Steel Corporation, Pittsburgh, Pa., 21 corporation of Pennsylvania Filed Oct. 24, 1966, Ser. No. 589,059 9 Claims. (Cl. 2293.5)

ABSTRACT OF THE DISCLOSURE Containers comprising body members constructed of steel foil and including a series of folds extending between the upper and lower edges of the body member and terminating short of said edges are disclosed.

This invention relates generally to containers made of steel foil and more particularly to steel foil containers which possess properties of high strength and flexibility.

Treated paperboard, treated cardboard and similar materials, as well as metal foils, such as aluminum foil or aluminum alloy foil have found application in the packaging art as container forming materials. Containers constructed from such materials often prove to be unsatisfactory, however, because they lack the necessary rigidity and strength to withstand shock without breaking, because they are often unable to maintain their shape under the weight of the material which they contain and because upon being subjected to a stress which causes them to deform, they fail to regain their origin-a1 shape when the stress is removed.

Containers which possess a greater tensile strength and which are more abrasion resistant than those constructed of the above mentioned materials can be made from steel foil. Thus the containers of my invention, because they are made of steel foil, have an inherent high strength but in addition to this inherent strength, the containers of my invention are of increased strength because the steel foil from which they are constructed is subjected to a strength-imparting folding operation prior to being formed into containers. Also, some of the containers of my invention are given a particular structural configuration which additionally contributes to the overall strength of the container. The folding operation to which the steel foil is subjected besides adding strength to the steel foil significantly renders the steel foil more flexible and resilient. The steel foil thereby can be more easily formed into containers of various shapes and configurations. The properties of flexibility and resiliency which the steel foil possesses as a result of this folding process are imparted to the containers formed from the steel foil so that the containers if subjected to a relatively severe deforming force will nevertheless regain their original shape when the force is released.

It is an object of my invention to provide high strength containers made from steel foil. Another object of my invention is to provide such high strength containers which are flexible and resilient. Another object of my invention is to provide steel foil containers which possess particular structural configurations which add to the strength of the containers. Yet another object of my invention is to provide steel foil containers which may be readily opened. A further object of my invention is to provide a process for strengthening steel foil. A still further object of my invention is to provide such a process which in addition renders the steel fo-il more flexible and resilient.

Various other objects and advantages will appear from "ice the following description of embodiments of my invention presently preferred by me and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

FIGURE 1 is a perspective view, partly in section showing a steel foil blank which has been folded in a manner according to my invention.

FIGURE 2 is a schematic illustration of the apparatus used in folding steel foil according to my invention.

FIGURE 3 is a perspective view of the rolls, partly in section, used in folding the steel foil.

FIGURE 4 is a perspective view of a container constructed of folded steel foil.

FIGURE 5 is a perspective view of the body of the container of FIGURE 4 prior to the affixing of end closures to the body Wall.-

FIGURE 6 is a perspective view, partly in section, of the end closures used in forming the container of FIGURE 4.

FIGURE 7 is a vertical cross-sectional view of the container of FIGURE 4 along its long axis.

FIGURE 8 is a side elevational View, partly in section of a partially completed tube-like container constructed of steel foil.

FIGURE 9 is a perspective view of the fully completed tube-like container of FIGURE 8.

The steel foil used in constructing containers according to my invention is of less than about .006 inch thickness and preferably the steel foil is of about .001 to about .004 inch thickness. Also, the steel foil most generally used in making the containers of my invention is full hard steel foil, that is, steel foil which is not annealed after being worked to gauge. While steel foil of different tempers are also used, the containers made from full hard steel foil possess a greater strength generally than those made from steel foil of different tempers. Steel foil of the above mentioned thicknesses is to be distinguished from ordinary tinplate used for making tin cans in that the latter is generally of a thickness greater than .007 inch and possesses properties different from the properties of steel foil. Thus for example, tinplate can be drawn to a considerable degree while steel foil for all practical purposes cannot be drawn between dies without rupturing. Additionally, ordinary tin cans require some type of an opening implement for opening of the can, whereas steel foil containers can be provided with tear strips whereby the container may be readily torn open. However, because it is quite thin, steel foil, even of the type which is strengthened according to my invention, cannot be used to make containers possessing as great a strength as tin cans. On the other hand, such steel foil containers possess a greater amount of flexibility and resiliency than ordinary tin cans.

While containers made of steel foil possess greater strength than containers made of materials such as treated paperboard and cardboard and non-ferrous metal foils, it is desired that even greater strength he imparted to steel foil containers for certain applications. Those mechanical processes known to persons skilled in the art for strengthening various types of sheet metal or metal foil, wherein embossments or strengthening ribs are provided in the sheet or foil, which processes include drawing or stamping the sheet or foil, are not applicable to is provided in the steel foil. In addition to strengthening the steel foil, the folding process renders the foil fiexible and resilient to a substantial extent, which properties are imparted to the containers constructed from the folded steel foil.

In folding the steel foil, it is necessary that each of the folds terminate short of the edges of the steel foil so that the folds do not extend across the entire width of the steel foil; otherwise, the steel foil will not be suitable for making containers, as will be more fully explained below. In order for the folds to so terminate the steel foil must necessarily be elongated or stretched somewhat at the fold ends. I have found, however, that by keeping the folds relatively shallow near the fold ends, the amount of elongation or stretching that occurs at the fold ends can be kept small enough to avoid rupturing the steel foil.

The nature of the folded steel foil will now be more fully explained with reference to FIGURE 1. This figure illustrates a steel foil blank after it has undergone a fold ing operation in accordance with my invention and preparatory to being made into a container body wall. The blank contains a series of folds which include downwardly folded portions 2 comprising a main portion 4 and terminal portions 1--1 and land portions 3 which folds terminate short of the edges of the blank to provide undeformed margins 55. In this particular embodiment, land portions 3 are in the same plane as undeformed margins 55. The undeformed margins are for the purpose of providing a suitable surface for the aflixing of the container end members after the blank is shaped into a container body wall. It must be recognized that these folds are made by a folding process as distinguished from a drawing or stamping process since as is known to those skilled in the art, the amount of elongation or stretching which can be carried out on steel foil before rupturing occurs is negligible. The elongation or stretching which does occur in my folding process occurs at the terminal portions 11 of the downwardly folded portions 2, The severity of this elongation depends upon the depth to which the downwardly folded portion extends just adjacent the terminal portions of the fold and for that reason the depth of the fold thereat is limited to that amount which will permit the fold to terminate by stretching of the steel foil without rupturing. The depth to which the downwardly folded portion extends at or near the central portion of the fold can, however, be somewhat greater than the depth of the fold just adjacent the terminal portions.

The process and apparatus for folding the steel foil will now be described with reference to FIGURES 2 and 3. FIGURE 2 is a schematic illustration of an embodiment of the apparatus used to fold the steel foil and includes a drive or feed roll 6 which by pressure against idler roll 11 feeds the steel foil from the conveyor rolls 9 to the folding or forming rolls 7 and 8. The feed and folding rolls are suitably driven so that the steel foil is delivered to the folding roll at the proper rate of speed as is well known in the art. The idler roll may also be driven for a more positive feed. The conveyor rolls 9 are positioned below the point of entry of the steel foil into the folding rolls and guid members 1010 are placed between the feed roll and folding rolls so as to aid in directing the steel foil to the folding rolls. Thus the steel foil first passes along the conveyor rolls in a first plane and is then delivered to a second plane spaced above the first plane to the folding rolls. I have found that by positioning the various components in the manner as described, creases which on occasion appear in the folded steel foil when the steel foil is fed to the folding rolls in a continuous horizontal plane and which extend across the folds in the foil distorting the desired folded structure are eliminated. I believe that the reason for this is that when the steel foil is delivered to the folding rolls along a single horizontal plane the folding rolls are in effect working on the entire length of the steel foil or at least upon an extended length of steel foil, and there is a greater tendency for the steel foil to bunch up at the point of foil entry into the folding roll so that creases result, whereas in the disclosed process the forming rolls work only on that short portion of foil which extends outwardly from the rolls to the guides and any tendency of the steel foil to bunch up is lessened. The steel foil after it is folded passes onto a delivery table where it is ready to be used to make containers.

The construction of the folding rolls which I have found to be particularly suitable for folding the steel foil in the desired manner is shown in FIGURE 3. The body of the bottom folding roll 8 has a generally concave configuration with the diameter of the roll increasing in both directions outwardly from the center of the roll and terminating in smooth end portions I t-14 which are of a uniform diameter and which define the undeformed margins 55 of the folded steel foil. Grooves 15 extend along the concave portion of the bottom roll and terminate at the end portions 14-14 of the roll. These grooves are about to 7 inch in width and are spaced apart by about 76 inch by ridges 16. The radius of curvuture of the grooves is about inch. The body of the top folding roll 7 has a generally convex configuration which is complementary with the concave configuration of the bottom roll and the top roll also terminates in smooth end portions 1919 which are of a uniform diameter and which engage the end portions 14-14 of the bottom roll when the rolls are in operation. The grooves 17 formed in the upper roll in a general way mesh with the ridges 16 in the bottom roll and the ridges 18 in the top roll mesh in a general way with the grooves 15 in the bottom roll. It is not essential, however, that meshing ridges and grooves be formed in the top and bottom rolls and a top roll can b provided with a smooth surface. This is because the top roll is made from a material which has a certain degree of resiliency such as urethane polymers, as compared to the bottom roll which is made of steel, and when the two rolls are brought into engagement sufficient engaging force is applied so that the upper roll is squeezed into the depressions in the lower roll where the rolls engage. Thus when the steel foil is fed through the rolls, the squeezed portions of the top roll force the steel foil into the grooves in the bottom roll, thereby folding the steel foil so as to form downwardly folded portions 2 whereby the steel foil is caused to generally assume the configuration of the grooves and ridges in the bottom roll. The top roll while it is somewhat resilient is sufficiently hard so that it can impart permanent folds to the steel foil. By providing a resilient top roll in this manner it can be seen that it is not necessary to align the rolls for exact meshing of complementary ridges and grooves in the rolls. As can be appreciated, the folding rolls can be constructed of various materials as long as a sufiicient differential in the hardness of the rolls is maintained so that one roll can be squeezed into the grooves of the other so as to permanently fold the steel foil.

Another result of providing essentially non-meshing rolls as described above is that the steel foil is folded from one side only whereby the folded steel foil blank is caused to roll up as it leaves the folding rolls so that it assumes the general configuration of the container it is to form. Thus as the steel foil passes through the folding rolls it is folded down into the bottom roll as described above but because no meshing of ridges and grooves necessarily occurs between the top and bottom rolls, no complementary folding occurs upwardly into the top roll and consequently all the folding occurs on only one side of the foil. As a result, when the foil exits from the folding rolls it rolls up on itself in a downward direction as illustrated in FIGURE 2. Because the containers made according to my invention possess in most cases a curved configuration with the top side of the steel foil as illustrated in FIGURE 2 forming the outside of the containers, the curved inclination which the steel foil assumes as it exits from the folding rolls assists in the shaping of the container as can be understood. Another result of folding the foil from one side in the manner described is that the undeformed margins remain in the same plane as the land portions.

In further recognizing the nature of the stretching or elongating which occurs at the fold ends it should be noted that as the steel foil passes between the rolls its end portions are tightly engaged by the smooth ends 14-14 and 19-19 of the top and bottom rolls and thus the folds produced in the steel foil cannot extend out to the ends of the steel foil but are forced to terminate where the steel foil enters between the smooth ends of the upper and lower rolls. As can be understood, that portion of the steel foil which is folded is gathered so that the length of that portion is shorter than the length which it possesses in an unfolded condition. At the same time, the undeformed margins of the steel foil because they are not folded do not change in length and to compensate for the relative change in length between the folded portion of the steel foil and the undeformed margins, it is necessary that the steel foil be elongated slightly at the fold ends while along the main portion 4 of the fold, no stretching or elongating of the foil occurs. Also as a result of the relative changes in lengths between the folded portion of the steel foil and the undeformed margins the containers constructed from the folded steel foil are given a somewhat hour-glass configuration which is more fully described below.

For some applications, the end portions 14-14 and 19-19 of the folding rolls are slightly knurled whereby the margins 5-5 of the steel foil are given a similar knurled structure for reasons as discussed below. The knurled structure on the folding rolls is sufficiently shallow so that no rupturing of the steel foil occurs.

While the above described process sets forth a specific folding technique which is presently preferred by me, it is to be understood that certain modifications may be made in my process of providing, steel foil of increased strength and flexibility. Thus for example, grooves and ridges can be provided in the top and bottom folding rolls so as to mesh upon rotation of the rolls thereby folding the steel foil from both sides. This would of course require that the respective grooves and ridges be exactly aligned in order to insure acceptable folds, and the feature of having the steel foil roll up on itself in a desired manner as discussed above would not necessarily occur when the foil is folded from both sides. The widths of the grooves and ridges of the folding rolls and consequently the widths of the downwardly and upwardly folded portions of the steel foil may be suitably varied as long as the properties of increased strength and flexibility are imparted to the foil. The depth of the grooves provided in the folding rolls and consequently the depth of the folds in the steel foil may also vary from that of the disclosed embodiment. The primary consideration in this regard is the depth of the downwardly folded portion just adjacent the terminal portions of the fold. That depth is limited to a degree which will enable the folds to terminate by stretching of the steel foil without any rupturing of the foil. The depth of the central portion of the fold can be somewhat greater than this limiting depth with the depth becoming gradually shallower in a direction away from the central portion towards the terminal ends of the fold.

In discussing the process of my invention I have referred to that process as a folding operation which produces folds in the steel foil and as can be seen from the foregoing discussion, the process is essentially one of folding wherein no stretching or elongating of the foil occurs except for the limited amount of stretching which appears at the ends of the folds.

Reference is now made to FIGURES 4 through 9 which illustrate novel containers made from steel foil which has undergone a folding operation as described above.

One type of container is illustrated in FIGURE 4 and comprises broadly a body member 20 of folded steel foil of about .002 inch thickness having plastic closures 21 and 22 secured to the ends thereof and a tear strip 23 for opening the container. In constructing a container of this type, i.e. a container with a tear strip, it is preferred to first secure the tear strip to an unfolded steel foil blank by means of an adhesive on that side of the blank which is to form the inside of the container. The tear strip comprises a strip of steel foil about one-quarter inch wide and extends across the blank parallel to and about one-half inch below that end of the blank which is to form the top of the container. The strip is sufficiently long as that a portion thereof extends beyond one side edge of the blank. The blank is then slit on either end of the tear strip at the point where it extends beyond the blank for reasons as will be explained below. The blank is then folded in a manner as described above so that the folds extend longitudinally of the blank from that edge of the blank which is to form the top of the container to that edge which is to form the bottom of the container. The two side edges of the blank are then brought into overlapping relationship and the overlapped portions secured together by means of an adhesive to form seam 24 and the body of FIGURE 5. The folds 2 extend between the upper and lower edges 25 and 26 of the body 20 and terminate short of said edges to provide undeformed upper and lower margins 55. The tear strip 23 circumscribes the inside of the body member with a portion 27 which extended beyond one side of the blank now extending outside the body member at the seam 24. This extending portion provides a pull tab which is grasped and pulled circurnferentially of the body member when the container is to be opened. The pull tab is covered with a plastic or other suitable material for ease and safety in gripping the tab upon opening the container. The slits 2828 which are provided in the blank enable opening of the package by the tear strip to be more easily initiated. As can be seen from FIGURE 5 and as was briefiy discussed above, the body possesses somewhat of an hourglass shape. Thus the body along its undeformed margins is of a greater diameter than along its folded portion. This feature comes about because of the manner in which the steel foil is folded as described above.

Each of the closure members 21 and 22 which are affixed to the upper and lower ends of the container respectrvely include a base portion 29 and a surrounding flange 30 which extends at approximately a right angle therefrom. The flange 30 includes a first portion 31 which extends in a direction away from the flange and a second portion 32 which extends in a direction towards the flange In a manner so as to provide a groove 33 which extends circumferentially about the closure member and which receives an undeformed margin of the body member 20. The end closures describe a peripheral configuration of two lobes smoothly merging into each other. The lobes are defined by arcs of circles and the merging portions by a smooth curve. The undeformed margins of the body member are inserted into grooves 33 and secured to the end closures by means of an adhesive and because the margins are not folded, a good bond and seal between the end closures and the body member is insured. The margins are in some instances knurled in a manner as described above so as to provide a greater surface area for bonding of the end closures to the body member. The body member, because it fits within the flanges of the lobular closure members, is constrained to assume the configuration of the latter and this lobular configuration contributes to the overall strength of the container. As will be understood by those skilled in the art, the container is filled through the unclosed end of the container after one of the end closures has been secured to the body and after the container is filled, the other end closure is similarly secured to the unclosed end.

To open the container and dispense the contents therefrom the tab 27 is grasped and pulled from right to left as shown in FIGURE 4. Steel foil, especially that of about .002 inch thickness or less has relatively low tear resistant qualities so that the container may be readily opened in the described manner. It is a characteristic of such steel foil that an extremely sharp edge is formed on any cut or free edge but by incorporating a tear strip in the container in the manner as described, the problem of sharp edge formation is overcome. This is because the tear strip causes the edge which is formed as the container is torn open to roll over to the point where any danger of sharp edge formation is greatly reduced as is more fully explained in my co-pending application Ser. No. 568,912, filed on July 29, 1966, to which reference is herein made. Besides being formed of steel foil the tear strip may comprise wire or any other material which has the characteristic of being able to roll over the torn edge of the steel foil as the container is torn open.

Containers of the general type described are also provided which do not incorporate a tear strip therein but in which the means provided for opening the container forms part of the end closure. Thus, end closures are provided which incorporate a spout therein. Additionally, end closures which can be readily torn away from the container are used. Further, the containers may be opened simply by breaking the adhesive seal between the end closure and the body member and removing the end closure 'therefrom or by using a piercing or cutting implement to open the container.

The end closures besides being made of plastic are also constructed from metals such as steel usually of a heavier gauge than steel foil or from paperboard.

While in the above described embodiment of my invention the container possesses only two circular lobes, containers are formed with any number of lobes, which lobes possess any type of generally smooth curve configuration in addition to the circular configuration of the illustrated embodiment.

In addition to containers possessing the lobular COnfiguration described above, containers are formed Which are of circular, elliptical, rectangular or square configuration. These containers also possess the various types of end closures described above.

Another embodiment of my invention is the tube-like container illustrated in FIGURES 8 and 9. The tube is constructed from steel foil which has undergone a folding operation as described above. To form the tube the two ends of a folded steel foil blank which are parallel to the folds are brought together in overlapping relationship and the overlapped portions secured to each other by means of an adhesive so as to form a cylindrical body. The body is then filled with the desired material. One end of the cylindrical body so formed is flattened along the undeformed margin and sealed thereat. A portion of the flattened margin 34 is then folded over and fastened to an upstanding portion 35 of the flattened margin by means of an adhesive and is sealed thereat. An elliptically shaped top closure and cap 37 are then secured to the open end 36 along the undeformed margin 38 by means of an adhesive to complete the construction of the tube. The closure has a flange 39 similar to the flanges provided on the closures 21 and 22 for securing of the top closure to the folded body. The body can also be sealed at its flattened end by other methods known to those skilled in the art and the top closure can be of any shape, for example, circular. This type of tube is especially effective as a container for viscous materials such as toothpaste, creams and greases. Because the folding operation renders the steel foil highly flexible and resilient the tube possesses these same characteristics. Therefore, when the tube is squeezed to dispense material therefrom and the tube is then released, the tube will flex back to its original shape and will not remain permanently deformed as do ordinary collapsible tubes, unless subjected to extreme pressure. When the tube returns to its original shape it acts in effect like a bellows and causes any material near the opening of the tube to be withdrawn there in. This eliminates waste and the associated mess which tends to form whennexcess material collects about the mouth of the tube.

Means used for performing the various sealing operations in forming the various containers of my invention include cold adhesives as described above as well as hotmelt adhesives, or further, the sealing procedures may be performed by weldingwhere applicable.

For some applications it is necessary or desirable to coat the steel foil with organic coatings such as microcrystalline waxes or plastics, or inorganic coatings such as zinc, tin, aluminum or the like. Such coatings will be necessary in some instances in order to protect the container from any adverse effects by the material contained therein. Also, steel foil-paper laminates can be used as container forming material with the laminates being folded in the same manner as described above.

It will be understood that various changes in the details, materials, steps and arrangement of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. A container comprising a body member having an upper edge and a lower edge, said body member being constructed of folded steel foil and including a series of folds extending between the upper and lower edges of the body member and terminating short of said edges so as to provide undeformed upper and lower margins on said body member, each of said folds having a downwardly folded portion comprising a main portion and a terminal portion at each end of said main portion, the depth of the downwardly folded portion along its main portion just adjacent said terminal portions being such as to permit the fold to terminate along said terminal portions by elongation of the steel foil without rupturing, and end closures secured to the undeformed margins of the body member.

2. The container of claim 1 wherein the steel foilis from about .001 to about .004 inch thick.

3. The container of claim 1 wherein the steel foil is full hard.

4. The container of claim 3 wherein the steel foil is from about .001 to about .004 inch thick and the depth of each of the downwardly folded portions is greatest near the center of the main portion with the depth being gradually less in both directions away from said center towards the terminal portions of the downwardly folded portion.

5. The container of claim 1 including a tear strip aflixed to the body member for opening of the container.

6. The container of claim 1 wherein said body member possesses a peripheral configuration of at least two lobes smoothly merging .into each other and wherein said end closures conform to the peripheral configuration of said body member.

7. The container of claim 6 including a tear strip aflixed to the body member for opening of the container.

8. A tube-like container comprising a body member having an upper end and a lower end, said body member being constructed of folded steel foil and including a series of folds extending between the upper and lower ends of the body member and terminating short of said ends so as to provide undeformed upper and lower margins on said body member, said lower undeformed margin forming a sealed flattened portion of the tube and a top closure member secured to the top of the tube along the upper undeformed margin, said top closure including means for permitting the material within the tube to be dispensed therefrom.

9. A steel foil blank for forming a container body wall, said blank including a series of substantially parallelfolds extending between two opposite edges of the blank, each of said folds terminating short of said edges so as to form undeformed margins adjacent said edges, each of said folds having a downwardly folded portion comprising a main portion and a terminal portion at each end of said main portion, the depth of the downwardly folded portion along its main portion just adjacent said terminal portions being such as to permit the fold to terminate 1 along said terminal portions by elongation of the steel foil without rupturing.

References Cited UNITED STATES PATENTS Puddefoot 22072 Pickop 220-72 XR Cooper 22072 Bates 220-72 Kinghorn et al 22951 Palmer 229-55 Bransten 229-3.5

DAVIS T. MOORHEAD, Primary Examiner. 

